linux-kernel - [patch V2 24/25] x86/apic/flat64: Remove the IPI shorthand decision logic

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Date:   Thu, 04 Jul 2019 17:52:09 +0200
From:   Thomas Gleixner <tglx@...utronix.de>
To:     LKML <linux-kernel@...r.kernel.org>
Cc:     x86@...nel.org, Nadav Amit <namit@...are.com>,
        Ricardo Neri <ricardo.neri-calderon@...ux.intel.com>,
        Stephane Eranian <eranian@...gle.com>,
        Feng Tang <feng.tang@...el.com>
Subject: [patch V2 24/25] x86/apic/flat64: Remove the IPI shorthand decision
 logic

All callers of apic->send_IPI_all() and apic->send_IPI_allbutself() contain
the decision logic for shorthand invocation already and invoke
send_IPI_mask() if the prereqisites are not satisfied.

Remove the now redundant decision logic in the APIC code and the duplicate
helper in probe_64.c.

Signed-off-by: Thomas Gleixner <tglx@...utronix.de>
---
V2: Remove the decision logic now that it is already done in the callers
    Drop the duplicate helper
---
 arch/x86/include/asm/apic.h         |    4 --
 arch/x86/kernel/apic/apic_flat_64.c |   49 ++++--------------------------------
 arch/x86/kernel/apic/probe_64.c     |    7 -----
 3 files changed, 6 insertions(+), 54 deletions(-)

--- a/arch/x86/include/asm/apic.h
+++ b/arch/x86/include/asm/apic.h
@@ -467,10 +467,6 @@ static inline unsigned default_get_apic_
 #define TRAMPOLINE_PHYS_LOW		0x467
 #define TRAMPOLINE_PHYS_HIGH		0x469
 
-#ifdef CONFIG_X86_64
-extern void apic_send_IPI_self(int vector);
-#endif
-
 extern void generic_bigsmp_probe(void);
 
 #ifdef CONFIG_X86_LOCAL_APIC
--- a/arch/x86/kernel/apic/apic_flat_64.c
+++ b/arch/x86/kernel/apic/apic_flat_64.c
@@ -76,33 +76,6 @@ flat_send_IPI_mask_allbutself(const stru
 	_flat_send_IPI_mask(mask, vector);
 }
 
-static void flat_send_IPI_allbutself(int vector)
-{
-	int cpu = smp_processor_id();
-
-	if (IS_ENABLED(CONFIG_HOTPLUG_CPU) || vector == NMI_VECTOR) {
-		if (!cpumask_equal(cpu_online_mask, cpumask_of(cpu))) {
-			unsigned long mask = cpumask_bits(cpu_online_mask)[0];
-
-			if (cpu < BITS_PER_LONG)
-				clear_bit(cpu, &mask);
-
-			_flat_send_IPI_mask(mask, vector);
-		}
-	} else if (num_online_cpus() > 1) {
-		__default_send_IPI_shortcut(APIC_DEST_ALLBUT, vector);
-	}
-}
-
-static void flat_send_IPI_all(int vector)
-{
-	if (vector == NMI_VECTOR) {
-		flat_send_IPI_mask(cpu_online_mask, vector);
-	} else {
-		__default_send_IPI_shortcut(APIC_DEST_ALLINC, vector);
-	}
-}
-
 static unsigned int flat_get_apic_id(unsigned long x)
 {
 	return (x >> 24) & 0xFF;
@@ -164,9 +137,9 @@ static struct apic apic_flat __ro_after_
 	.send_IPI			= default_send_IPI_single,
 	.send_IPI_mask			= flat_send_IPI_mask,
 	.send_IPI_mask_allbutself	= flat_send_IPI_mask_allbutself,
-	.send_IPI_allbutself		= flat_send_IPI_allbutself,
-	.send_IPI_all			= flat_send_IPI_all,
-	.send_IPI_self			= apic_send_IPI_self,
+	.send_IPI_allbutself		= default_send_IPI_allbutself,
+	.send_IPI_all			= default_send_IPI_all,
+	.send_IPI_self			= default_send_IPI_self,
 
 	.inquire_remote_apic		= default_inquire_remote_apic,
 
@@ -216,16 +189,6 @@ static void physflat_init_apic_ldr(void)
 	 */
 }
 
-static void physflat_send_IPI_allbutself(int vector)
-{
-	default_send_IPI_mask_allbutself_phys(cpu_online_mask, vector);
-}
-
-static void physflat_send_IPI_all(int vector)
-{
-	default_send_IPI_mask_sequence_phys(cpu_online_mask, vector);
-}
-
 static int physflat_probe(void)
 {
 	if (apic == &apic_physflat || num_possible_cpus() > 8 ||
@@ -267,9 +230,9 @@ static struct apic apic_physflat __ro_af
 	.send_IPI			= default_send_IPI_single_phys,
 	.send_IPI_mask			= default_send_IPI_mask_sequence_phys,
 	.send_IPI_mask_allbutself	= default_send_IPI_mask_allbutself_phys,
-	.send_IPI_allbutself		= physflat_send_IPI_allbutself,
-	.send_IPI_all			= physflat_send_IPI_all,
-	.send_IPI_self			= apic_send_IPI_self,
+	.send_IPI_allbutself		= default_send_IPI_allbutself,
+	.send_IPI_all			= default_send_IPI_all,
+	.send_IPI_self			= default_send_IPI_self,
 
 	.inquire_remote_apic		= default_inquire_remote_apic,
 
--- a/arch/x86/kernel/apic/probe_64.c
+++ b/arch/x86/kernel/apic/probe_64.c
@@ -36,13 +36,6 @@ void __init default_setup_apic_routing(v
 		x86_platform.apic_post_init();
 }
 
-/* Same for both flat and physical. */
-
-void apic_send_IPI_self(int vector)
-{
-	__default_send_IPI_shortcut(APIC_DEST_SELF, vector);
-}
-
 int __init default_acpi_madt_oem_check(char *oem_id, char *oem_table_id)
 {
 	struct apic **drv;